Vacuum belt guiding means

ABSTRACT

Herein is disclosed directional influencing apparatus for strip stock such as a traveling web or sheets, employing a traveling recirculatory vacuum belt controllably shifted to variable angular orientation.

United States Patent Black et al.

[ 1 July 25, 1972 VACUUM BELT GUIDING MEANS [72] Inventors: James A. Black, Kent City; Harry Russell Farwell, Cedar Springs, both of Mich.

[73] Assignee: James A. Black, Kent City, Mich.

[22] Filed: Feb. 26, 1971 [21] Appl. No.: 119,181

521 u.s.c| ..226/3,226/l9,226/95 s11 Int.Cl ..B65h25/06 5s FieldofSeai-ch ..226/95,l5,l9,l8,2l,7,

[56] References Cited UNITED STATES PATENTS Shields ..226/95 3,425,610 2/1969 Stewart ..226/17O X 3,489,325 1/1970 Epstein et al. ..226/95 X 3,587,962 6/1971 Hetzhoff ..226/95 Primary ExaminerRichard A. Schacher Assistant ExaminerGene A. Church Attorney-Price, Heneveld, Huizenga & Cooper 57 ABSTRACT Herein is disclosed directional influencing apparatus for strip stock such as a traveling web or sheets, employing a traveling recirculatory vacuum belt controllably shifted to variable angular orientation.

16 Claims, 5 Drawing Figures mmwzm 3,679,112

- SHEET 1 0F 2 I NVEN TOR5 BY @iW VACUUM BELT GUIDING MEANS BACKGROUND OF THE INVENTION This invention relates to apparatus for influencing flexible stock, and particularly to a recirculating vacuum belt stock positioner.

Traveling web stock is usually guided in its continuous movement by laterally positioned fences or rails which the web edges abut, and/or by restraining edge rollers and the like. Such devices work effectively for much web stock. However, it has been learned by the inventors herein that flexible film type web stock, particularly thin polymeric film stock, is not effectively restrained by such fences and the like. Rather, the film bends and climbs over the fences, causing disruption of the processes performed thereon and damage to the film.

SUMMARY OF THE INVENTION A primary object of this invention therefor is to provide novel web guiding apparatus, capable of controlling even thin, flexible polymeric film type web stock. It requires no side fences, rollers, or the like.

Another object of the invention is to provide position influencing apparatus for strip stock, whether in the form of a web or sheets.

The apparatus moves traveling strip stock, applying a laterally biasing force thereto relative to the direction of travel of the stock. It has been found to be particularly efiective for web stock of the thin highly flexible type such as polymeric film stock, in contrast to prior devices.

The novel apparatus employs a recirculatory vacuum belt engaging the stock and biasing it in either lateral direction by shifting to controlled angularity relative to the direction of stock travel. When used on web stock, no tension on the web is necessary. Yet the apparatus functions effectively on webs that are under tension. Alignment can be effected in one plane. Another object is to provide such apparatus that operates effectively on webs that are continuously or intermittently advanced.

The vacuum belt is preferably responsive, through a responder, to a stock position sensor, to automatically control the stock.

These and other features, objects, and advantages will be apparent from a study of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a traveling web arrangement, illustrating the invention;

FIG. 2 is a fragmentary enlarged plan view of a portion of the apparatus in FIG. 1;

FIG. 3 is an enlarged plan view of the stock shifting suction belt of the invention;

FIG. 4' is an elevational view of the apparatus in FIG. 3; and

FIG. 5 is an end elevational view of the apparatus in FIGS. 3 and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Since the invention herein was primarily developed for and operates so effectively relative to traveling web stock, it will be largely explained with respect thereto. A web is considered to be a more or less continuous elongated length of flexible material such as paper, polymeric film or the like, laminated stock, or other similar materials. In the broader aspects of the concept disclosed, it will be apparent that the apparatus could also be effectively employed on sheets, for guiding, collating, and the like.

Referring now specifically to the drawings, the equipment is illustrated to include the inventive guiding apparatus 12, a web slack receiving container 14, an idler roll l6-for the web W, and a windup roll 18 for the web.

Web guiding apparatus 12 has a web engageable, recirculating suction surface means formed by a recirculating belt subassembly 20 pivotally mounted to shift angularly as shown by the phantom lines in FIG. 2. It is shifted by power means formed by bellows unit 24 operated by a vacuum pump or other suction source 26 through conduit 28. Recirculating device 20 includes a flexible belt 30 having a web engaging outer peripheral surface area. Belt 30 travels around a pair of pulleys 32 and 34. These pulleys can be free wheeling or one or both could be powered if desired. These are rotatably mounted at opposite ends of apparatus 20 on axles 36 and 38 respectively. If a pulley is to be driven, a flexible drive shaft could be operably connected to an axle of the pulley, or other equivalent drive means employed. These axles are mounted on a pair of spaced, parallel, elongated plates 40 and 42 which in turn are secured to a generally U-shaped mount 46. Belt 30 has a plurality of suction orifices 31 around its periphery at spaced intervals. These orifices are in communication with a manifold 50 between the passes of the belt and underlying the surface of the upper belt pass adjacent the traveling web to be influenced. Manifold 50 communicates through conduit 52, pipe connection 54, and flexible conduit 56 with a suitable vacuum pump or other suction source 58. This enables suction to be applied through orifices 31 to the under-surface of web W engaged by the belt, to temporarily pull the web against and under the influence of belt 30.

Mount 42 is pivotally supported on a suitable bearing 60 to a fixed plate 62, allowing pivotal movement of the belt and its associated components about its central portion relative to the fixed support 62, under the influence of the bellows actuator 24. Bellows 24 is contractible upon increase of vacuum or suction to its interior through conduit 28. Such retraction pivots the ends of subassembly 20 about its center, so that the end of subassembly 20 to which the bellows is connected by a connecting rod pivots towards the bellows, while the opposite end pivots away therefrom. Movement in the opposite direction is caused by a coil spring biasing means 72 with decrease in the suction to the bellows. The coil spring will bias subassembly 20 to its center position or further to a position where the end of unit 20 closest the spring pivots toward the spring, while the opposite end pivots in the opposite direction as illustrated by the phantom lines in FIG. 2.

Spring 72 tends to pivot the unit to one angular extreme while full suction on bellows 24 tends to pivot the unit to the opposite angular extreme.

The amount of negative pressure or suction in bellows 24, generally regulated by control valve 76, is constantly varied by the amount of air flow which is allowed to pass through orifice 78 of a web edge sensor 79. This orifice communicates through conduit 28 to main conduit 28. Thus, when at least part of the orifice is uncovered, the negative pressure in bellows 24 decreases, giving more effect to spring 72. But, when web W becomes laterally displaced while traveling as indicated by the arrow in FIG. 2, and partially or completely covers orifice 78, the amount of negative pressure in conduit 28 and 28 will increase an amount governed by the degree of cover of the orifice, causing bellows 24 to contract a controlled amount, thereby shifting subassembly 20 to a controlled angular orientation relative to the direction of web movement. Angular pivoting of the apparatus is limited by a pair of alternate set-screws 84 and 86 or the equivalent which form stops. These are mounted to upstanding plate 63 on one edge of member 62.

Belt 30 is preferably restrained against lateral movement relative to pulleys '32 and 34 by restraining means such as flanges 41 straddling belt 30 on its underpass. In operation of the novel system, vacuum sources or pumps 26 and 58 are in operation while web W is traveling either in continuous motion or intermittently, with or without tension applied thereto. As the web travels in the direction indicated by the arrows, if it becomes displaced laterally so that an edge of the web covers at least a portion of sensor orifice 78, the negative pressure applied by suction unit 26 through conduit 28 to the bellows 24 increases because of the decrease of air flow through conduit 28'. This increase in suction contacts bellows 24 a controlled amount, pulling rod 70 to pivot unit through a controlled angular orientation relative to the direction of web travel, against the bias of tension spring 72. Belt is drawn to the undersurface of the traveling web by suction orifices 31, and travels around its free wheeling pulleys due to the coupled engagement with the traveling web. The speed of the belt will vary with its angular vector position relative to that of the web, nicely accommodating the web movement. Its angular movement biases web W a controlled lateral amount relative to the direction of travel as the web proceeds, thereby gradually shifting it laterally a controlled amount. When the belt is so shifted, the sensor orifice is uncovered, causing bellows power unit 24 to expand and shift the belt back to a position toward alignment with the belt direction of travel. The unit therefore constantly maintains the web in controlled position, as has been demonstrated repeatedly with experimentation of this equipment. It has been found effective even for very thin highly flexible polymeric films e.g. polyethylene or polypropylene, which are practically impossible to control relative to their lateral position using the conventional guiding techniques. The number and position of such devices may be widely varied to suit particular conditions, web material, and the like. in addition, a plurality of laterally spaced sensors and/or sensor orifices may be provided, and/or the configuration of the orifice or orifices may be used for even more graduated control and response.

Hence, since it is conceivable that certain details of this construction may be modified while using the concept presented herein, it is intended that the invention is to be limited only by the scope of the appended claims and the reasonable equivalents to those defined therein rather than by the details of the illustrative embodiment.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

1. Guiding apparatus for flexible stock comprising: stock engageable, recirculating surface means having suction orifice means for drawing the surface of the stock to it; suction means operably associated with said orifice means; support means for said recirculating surface means, being shiftably mounted to allow said recirculating surface means to move at controlled angular orientation for influencing the direction of movement of the stock.

2. The guiding apparatus in claim 1 wherein said recirculating surface means comprises a belt.

3. The guiding apparatus in claim 1 wherein said support means is pivotally mounted to assume the various angular positions.

v4. The guiding apparatus in claim 1 including power shift means operably associated with said support means to shift it to controlled angles.

5. Guiding apparatus for a traveling web comprising: web engageable, recirculating surface means having suction orifice means for drawing the web surface to it; suction means operably associated with said orifice means; support means for said surface means, being shiftably mounted to allow said recirculating surface means to move at controlled angular orientation relative to the web direction of travel for guiding the web.

6. The web guiding apparatus in claim 5 wherein said recirculating surface means comprises a belt.

7. The web guiding apparatus in claim 5 wherein said recirculating surface means comprises a belt mounted on pulleys.

8. The web guiding apparatus in claim 7 wherein said pulleys are free wheeling to allow said belt to automatically accommodate the rate of movement of the web under the influence thereof.

9. The web guiding apparatus in claim 5 wherein said support means is pivotally mounted to assume the various angular positions relative to the web direction of travel.

10. The web guiding apparatus in claim 5 including power shift means operably associated with said support means to shift it to controlled angles. I

ll. The apparatus in claim 10 including web sensor means positioned to sense web edge location and operably associated with said power shift means to constantly control web position by shifting said surface means for influencing the web.

12. Guiding apparatus for a traveling web comprising: a web engageable recirculating suction belt mounted on a pair of free wheeling pulleys and having a plurality of suction orifices for drawing a web surface to it; suction means operably associated with said orifice means; said pulleys being mounted on a support means and said support means being pivoted on an axis normal to the belt travel to enable said belt to be variably angularly oriented relative to the web direction of travel, allowing said suction belt to influence a traveling web a controlled amount in a lateral direction as said belt travels around its pulleys under the influence of said web.

13. The web guiding apparatus in claim 12 including: vacuum operated power shifting means operably associated with said support means to pivot such and said suction belt to different angles; and suction web edge sensor means positioned to sense the edge of a laterally displaced web, and operably associated with said suction means and said power shifting means to activate the latter in response to sensing of the position of a web edge, for pivoting the suction belt to laterally influence the web relative to said sensor means.

14. The method of influencing the lateral position of flexible stock traveling in a main direction of travel comprising the steps-of: providing a movable suction surface; positioning said suction surface immediately adjacent the surface of a traveling stock; applying suction to said suction surface to draw said suction surface and the traveling stock together, causing said suction surface to move with the stock; and varying the angular orientation of the direction of movement of said suction surface relative to the direction of travel of the stock.

15. The method in claim 14 wherein said suction surface is allowed to move freely, to thereby be moved by said traveling stock.

16. The method in claim 14 including the step of: sensing the lateral position of the stock and varying the angular orientation of said suction surface in response thereto. 

1. Guiding apparatus for flexible stock comprising: stock engageable, recirculating surface means having suction orifice means for drawing the surface of the stock to it; suction means operably associated with said orifice means; support means for said recirculating surface means, being shiftably mounted to allow said recirculating surface means to move at controlled angular orientation for influencing the direction of movement of the stock.
 2. The guiding apparatus in claim 1 wherein said recirculating surface means comprises a belt.
 3. The guiding apparatus in claim 1 wherein said support means is pivotally mounted to assume the various angular positions.
 4. The guiding apparatus in claim 1 including power shift means operably associated with said support means to shift it to controlled angles.
 5. Guiding apparatus for a traveling web comprising: web engageable, recirculating surface means having suction orifice means for drawing the web surface to it; suction means operably associated with said orifice means; support means for said surface means, being shiftably mounted to allow said recirculating surface means to move at controlled angular orientation relative to the web direction of travel for guiding the web.
 6. The web guiding apparatus in claim 5 wHerein said recirculating surface means comprises a belt.
 7. The web guiding apparatus in claim 5 wherein said recirculating surface means comprises a belt mounted on pulleys.
 8. The web guiding apparatus in claim 7 wherein said pulleys are free wheeling to allow said belt to automatically accommodate the rate of movement of the web under the influence thereof.
 9. The web guiding apparatus in claim 5 wherein said support means is pivotally mounted to assume the various angular positions relative to the web direction of travel.
 10. The web guiding apparatus in claim 5 including power shift means operably associated with said support means to shift it to controlled angles.
 11. The apparatus in claim 10 including web sensor means positioned to sense web edge location and operably associated with said power shift means to constantly control web position by shifting said surface means for influencing the web.
 12. Guiding apparatus for a traveling web comprising: a web engageable recirculating suction belt mounted on a pair of free wheeling pulleys and having a plurality of suction orifices for drawing a web surface to it; suction means operably associated with said orifice means; said pulleys being mounted on a support means and said support means being pivoted on an axis normal to the belt travel to enable said belt to be variably angularly oriented relative to the web direction of travel, allowing said suction belt to influence a traveling web a controlled amount in a lateral direction as said belt travels around its pulleys under the influence of said web.
 13. The web guiding apparatus in claim 12 including: vacuum operated power shifting means operably associated with said support means to pivot such and said suction belt to different angles; and suction web edge sensor means positioned to sense the edge of a laterally displaced web, and operably associated with said suction means and said power shifting means to activate the latter in response to sensing of the position of a web edge, for pivoting the suction belt to laterally influence the web relative to said sensor means.
 14. The method of influencing the lateral position of flexible stock traveling in a main direction of travel comprising the steps of: providing a movable suction surface; positioning said suction surface immediately adjacent the surface of a traveling stock; applying suction to said suction surface to draw said suction surface and the traveling stock together, causing said suction surface to move with the stock; and varying the angular orientation of the direction of movement of said suction surface relative to the direction of travel of the stock.
 15. The method in claim 14 wherein said suction surface is allowed to move freely, to thereby be moved by said traveling stock.
 16. The method in claim 14 including the step of: sensing the lateral position of the stock and varying the angular orientation of said suction surface in response thereto. 